Apparatus for indicating and recording speed of rotating shafts.



No. 675,564. Patented June 4, I90l. W. G. KENT 8. J. GORDON. APPARATUSFOR INDICATING AND RECORDING SPEED OF ROTATING SHAFTS.

(Application filed on. 2, 1000.) (No Model.) 2 Sheets-Sheet l.

ATTORNEYS Inc- Imam pzrzas w. mowau-ma, msumtrcm. n. cy

Patehtod June 4, l90l.

W. G. KENT &. J. GORDON. APPARATUS FOR INDICATING AND RECORDING SPEED OFROTATING SHAFTS.

(Application filed Oct. 2, 1900.)

2 Sheets-Sheet 2.

(N0 Nodal.)

Ill YfNTORS.

AITOHNEYS UldlllllED dramas PATENT OFFICE.

'WALTER G. KENT AND JOHN GORDON, OF LONDON, ENGLAND.

APPARATUS FOR lNDlCATlNG AND RECORDING SPEED OF ROTATING SHAFTS.

SPECIFICATION forming part of Letters Patent No. 675,564, dated June 4,1901. Application filed October 2, 1900. Serial No. 81,768. (No model.)

To aZZ whom it may concern.-

Be it known that we, WALTER GEORGE KENT and JOHN GORDON, subjects of theQueen of Great Britain and Ireland, residing at London, England, haveinvented a new and Improved Apparatus for Indicating and RecordingSpeeds of Rotating Shafts, (for which we have made application forLetters Patent for partthereof in Great Britain under No. 6,137, datedApril 2, 1900,) of which the following is a specification.

This invention relates to a gage capable of giving a permanent record ofthe velocity with which a shaft of an en ine or motor, such as that of asteamer, is moving at any time and is characterized by means whichadapts the device, first, to give an exaggerated and distinctly visibleindication immediately the engine starts; second, to give automaticallyand without personal attention a prompt and distinct indication of thereversal of the movement of the engines-i. a, when going astern in asteamer; third, to be unaffected by the motion of a vessel within whichit may be placed; fourth, to be unaffected by the relative distances ofvarious gages or indicators placed at any reasonable distance above oraway from the device; fifth, to give an artificially reduced andcompressed scale of intervals and of pressures producing the same forlarge variations of speed to keep the gage within the mechanical limitsof an ordinary pressure-gage, and, sixth, a relief to be afforded to thepressure'gages at a fixed limit of racing speed, the records so obtainedin a steamer giving an absolute chart and time record of starts, anyvariations of speed, stoppages, reversal of engines, and even thecondition of weather or disturbances of the sea deducible from therecorded momentary variations of speed in the engines. To effect thesevarious and important results, We use and find it necessary to use, incombination, a liquidcirculating pump, preferably of the multipleplunger type, adapted so that the stream of liquid therethrough shall bereversed as regards its issue upon reversal of the crank operating suchpump; a controlvalve between the issue and the suction of such pumpadapted to open only in one direction after a certain minimum pressurehas been set up in the liquid to automatically corders at various varythe area of the affected orifice it gives according to pressure upon thevalve to have a constant relief bypass, and to close upon reversal ofthe stream except for such small by-pass, a communication by air fromthe delivery-pressure of such pump to gages or repoints, and acompactness of structure in the pump and liquid-reservoirs.

WVe are aware that pumps operated by a rotating shaft have been devisedand are on record for the purpose of indicating by the pressure ofdelivery ofsuch pumps either direct from such liquid or from animprisoned volume of air communicating such pressure for the indicationof the speed of such rotating shaft; but the omission to obtain any oneor other of the above desiderata has been i found to mar the commercialsuccess of such devices, and so far as we are aware a combination ofdevices adapted to produce the above desiderata is not as yet known.

In order that our invention may be the better understood, We will nowproceed to describe the same with reference to the drawings heretoannexed and to the letters inserted thereon.

Figure 1 is a diagrammatic representation of the general arrangement ofour apparatus. Fig. 2 is a sectional View through the reservoir. Fig. 3is an enlarged vertical section through the pump. Fig. 4 is a sideelevation of the pump. Figs. 5 and 6 are details of the valve andseating used for said pump. Fig. 7is an enlarged vertical sectionthrough the return-orifice of circulation and the control-valve betweenthe discharge and suction of said pump, and Fig. 8 is a perspective Viewof the valve in said orifice.

To carry out our invention, We employ a triple-cylinder single-actingpump A, such construction being preferred as best adapted for liquidtightness with slow speed of revolution and long life without attention.The said pump is driven through any convenient form of belt-band orchain attachment or gearing B from the rotating shaft O of any steamengine or motor of which the speed of revolution is desired to beindicated or recorded. Such pump is affixed to one side of a centraldiaphragm d of a double box or reservoir D for liquid, such as oil, andthe pump A forms a means of circulation of the liquid or points thescale may be magnified.

oil from one compartment 01 (which is normally the supply or suctioncompartment) to the other CF. The compartment 61 of the said box orreservoir, which is the deliverycompartment under normal circumstances,serves as an air-chamber, the upper part of the said compartment and thepipes e (leading to the various gages or recorders E E) being filledwith an imprisoned volume of air.

Between the two compartments d and d is a communication nozzle or shortpipe F, Figs. 2, 7, and 8, which is fitted with a control-valve f, heldup against the normal direction of discharge from d to d by a spring G.This valvef fills the neck of its seating byits tubular body, exceptfora small weep around the same, and preferably through a niche orgroove f in the hand of the valve; but such weep may be provided by anysmall by-pass, which allows any difference of pressure in the twocompartments to cause the liquid or oil to weep through untilequilibrium is restored. The tubular body of the valve is cut with oneor more longitudinal slots f up to the head, such slots being made ofvariable width as may be desired, but tending to increase in area fromthe head to the tail of the valve.

When the pump is at rest, the valve f is on its seating. Upon thestarting of the pump with discharge into the compartment d the pressuretherein is immediately raised by the compression of the air therein,giving an immediate record of starting upon the gages or recorder. Thevalvef is then gradually raised from its seating, uncovering theexpanding slots f thereby increasing the effective area of the valve aspressure increases in the chamber 61 and thus reducing the rise ofpressure for increase of speed of the pump A, which rise would otherwisebe as the square of the speed, and increase in too rapid increments. Atthe same time should an exceptionally large scale be required at certainintervals of speeds by a reduction of the area of the slot between suchAs a precaution against excessive pressure in the gages beyond workinglimits-that is, when the engines are racing-a large sudden increase inthe area of the slot or slots f may be made at the limit of practicalobservation. Thus an immediate and exaggerated indication and record ofthe starting of the engine, even at the slowest speed, may be obtainedupon the dial of any suitable pressure-gage, such as a Bourdon oraneroid, and this indication may be made a matter of record by the knownrevolving and recording cylinder, marked by a pencil from the saidpressuregage, all of which being well-known devices need not be furtherdescribed in detail.

In order that an immediate and marked indication by vacuum may beautomatically obtained on the said gages and recorders by our apparatus,we operate the opening and closing of the suction and discharge of thepump mechanically from the pump-driving shaft, so that upon reversal ofthe direction of the pump-shaft the direction of discharge from onechamber, d to the other, (1 will be reversed, and as our control-valvef, before described,situated in the communication-pipe between thechambers, immediately closes, except for the aforsaid small weep throughthe valve, a partial vacuum is at once set up in the aforesaid dischargeor air chamber (i when the oil is withdrawn therefrom and delivered intothe almost-closed chamber 61 .which was normally the supply or suctionchamber. To carry this out, we bring the three supply-ports g, Fig. 3,of the respective pump-cylinders to a central valve face or block G,having apertures g therein of peculiar crescent shape, corresponding tothe said cylinder-ports, and to this valve-face we fit a disk valve 11,having a circular pocket h on its under face toward the ports. In thecenter of the valve-face G are also a series of apertures p from thesuction or supply pipe P, carried into the supply-chamber d The saiddisk valve H is mounted upon an eccentric 7b, which is caused to revolveon a spindle (footed into the valve face G) by a small return crank-arm7t from the pump crank-shaft K. The disk valve thus makes both a rotaryand a traversing movement about the valve-face G, uniting in successionthe cylinder-port apertures g with the central suction-supply P, whileat the same time the port-apertures g are exposed in succession beyondthe rim of the disk valve H for discharge into the crankchamber Q, whichcommunicates with the discharge or pressure chamber d by the apertures qq in the diaphragm. The discharge into the chamber d from thereturn-valve F is carried by a glide or trough R, adapted to preventfrothing of the oil as far as possible. This disk valve so operated thusserves to control the suction to and discharge from all thepump-cylinders, and by its combined rotary and translating movementcannot score or groove the valve-face, but must wear uniformlythereover. Further, as the pocket h in the said valve is a perfectannulus the valve is not fixed tightly on its driving eccentric tumbler,but may shift its position on the eccentric without interference withits function. It is kept upon its face by the external pressure ofdischarge in the pressurechamber 01 It will be noticed also that uponreversal of the direction of rotation of the pump crank-shaft thedirection of flow of the pumped oil is reversed, the discharge-aperturesg becoming the suction-apertures and the discharge being through thesuction-ports into the original suction or supply chamber d thus givingautomatically an immediate partial vacuum in the former pressure-chamber(1 and thus to the gages.

By the compact arrangement of the pump A within its own divided suctionand pres sure reservoir and by the fact that all fluidpressure iscommunicated by air the whole apparatus is unaifected as regardsirregularity of liquid-pressure by the movement or pitching or tossingof a vessel or other structure to which it may be applied.

Having now described this invention, what we claim, and desire to secureby Letters Patent, is

1. Arotating-shaftspeed-indicator,consisting of, in combination, a pumpcircnlatinga liquid between two compartments; connections between saidshaft and pump to produce isoclironous rotation; a mechanicallyinovedpump-valve, determining reversal of flow of liquid between saidcompartments for reversal of pump-shaft; a comm unieation between saidcompartments to complete circulation; an automatic control-valve in saidcommunication, springloaded against 11ormal flow, adapted to close onreversal of flow through said communication; a small by-pass around saidvalve and an imprisoned air volume in discharge-chamber, and in pipecommunications, to known gages and recorders.

2. In a rotatingshaft speed-indicator, in combination, a divided oilorliquid reservoir; a reciprocating pump having three singleacting'cylinders, fixed in one compartment of said reservoir; a suctionadmission to central valve-face from the said compartment of saidreservoir; a disk valve on said valveface, having an annular pocket onunder face, apertures from each cylinder-port on said valve-facecommunicating with discharge compartment; an eccentric embedded incenter ofsaid disk valve; connections from pumpcrank to revolve saidcentral eccentric,to give a rotary and translating movement of saidvalve over said valve-face; a communication between parts of saiddivided reservoir having a spring-pressed control-valve, closing, exceptfor small weep, on reversal of circulation; and an imprisoned air volumein one part of said reservoir communicating with pressure-gages.

3. In a rotating-shaft speed-indicator, in combination, a divided oil orliquid reservoir;

a reciprocating pump in one compartment thereof; ports through said pumpcontrolled by a mechanically-moved valve to effect displacement of oilor liquid from one compart- 5 ment to the other; a further communicationbetween compartments to complete circulation; a spring-pressedcontrol-valve in said communication; a slight by-pass through or aroundsaid valve; longitudinal slots through 5 tubular body of said valve ofvariable width; and an imprisoned air volume in one part of saidreservoir communicating with pressuregages.

4. In a rotating speed-shaft indicator, in 6 combination; a divided oilor liquid reservoir; a pump in one compartment adapted to displace oilor liquid from one compartment to the other and to reverse displacementupon reversal of driving-shaft; a further commu- 6 nication betweencompartments to complete circulation; a spring-pressed control-valve insaid communication adapted to give variable area of issue, and to closeon reversal of stream, a slight by-pass through or around 7 said valve;and an imprisoned air volume in part of said reservoir communicatingwith pressure-gages.

5. In combination; single-acting pump-bar rels distributed about acrank-shaft; ports 7 from said pump-barrels to a central valveface; acentral exit port or ports in center of said valve-face; an annularinverted troughvalve over said ports; a spindle in center of saidvalve-face; and an eccentric turning 011 8 said spindle, Within the bodyof said annular valve to determine control of issue and inlet ports ofsaid pump according to the direction of rotation of the drivingcrankshaft.

In Witness whereof we have hereunto set 8 our hands in presence of twowitnesses.

\VALTER Gr. KENT. JOHN GORDON.

Witnesses:

JOHN C. FELL, RICHARD A. IIOFFMANN.

